"It took but a laugh for everything to collapse, for the land to be lost." Liu Zongyuan (7th century)
It was not out of carelessness that the Song Dynasty lost its power, but through its pacifism, through sovereigns who strove to resolve conflicts through conciliation, alliances, and tribute money instead of battle. But the fact is that their fron- tiers were porous, and that the Mongol hordes pushed forward until, in 1135, they had invaded all of North China, forcing the government to withdraw to Hangzhou. Social unrest continued to weaken the Song, and one and a half centuries later, they succumbed to the Mongol troops. The Mongol chief, Kublai Khan (grandson of Genghis Khan), founded the Yuan Dynasty, with a capital at Da Du ("Grand Capital"), the future Peking (Beijing). Contrary to received opinion, under the Yuan, China enjoyed a period of peace and grandeur both economically and culturally speaking. Their painting and ceramics, although a continuation of the Song line of production, were of outstanding quality. To the Yuan, however, belongs the honor of having produced the first pieces of a cobalt blue porcelain, of the sort that would blossom under the Ming.